IMO it will be fine. Its simply running, i expect, auto transmission fluid mixed at a low level with a synthetic engine oil so I doubt that it would cause any problems at all in the short term. The Porker should be fine to get to the local dealer, no problems at all.

Modern oils wouldnt attack the seals like old fashioned ones would. (They used to cause shrink and swell, leaving a right old mess but im confident a modern synthetic wont do this.)

Dont enter the Le Mans in it though, as occasionally woolly steering feel from the easier to compress multigrade may cause a crash.